Work holding device



July 27, 1954 Filed Aug. 24, 1949 G. F. WALES ETAL WORK HOLDING DEVICE 2Sheets-Sheet l INVENTORS GEORGE/T144459 "#0 PAUL 720201? fm y ATTOE/YE'Y y 7, 1954 G. F. WALES ET AL 2,684,355

WORK HOLDING DEVICE Filed Aug. 24, 1949 2 Sheets-Sheet 2 mum: 47 Q :22I; \EIKQE/ J g I W /72 mm. V 4

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Patented July 27, 1954 WORK HOLDING DEVICE George F. Wales, Kenmore, andPaul H. Taylor, North Tonawanda, N. Y., assignors, by direct and mesneassignments, to Wales-Strippit Corporation, North Tonawanda, N. Y., acorporation of New York Application August 24, 1949, Serial No. 112,134

3 Claims. 1

This invention relates to improvements in work holding devices, beingconcerned more particularly with a device characterized by featureswhich adapt it particularly, but which do not necessarily so limit it,to the support of workpieces in such a manner that they may be turnedabout a center which bears a predetermined relation with respect to awork-performing tool or other instrumentality. The device, therefore, isavailable, among other purposes, for rotatably supporting work-pieces insuch a relation with respect to a nibbler or other punching element thatthe work-pieces may be formed into circular or other shapes havingcurved exteriors or may be punched or perforated in any desired mannerat points equidistant from a predetermined center.

One object of the invention is to provide a device which is so designedthat it may be availed of to hold work-pieces in various ways, therebyenabling any particular work-piece to be held in the manner best adaptedto its physical characteristics, those of the machine with which it isassociated and the nature of the operation to be performed.

Another object is to provide a device which is readily adjustable toaccommodate work-pieces of various sizes and to support them in variouspositions with relation to the work-performing tool.

Yet another object of the invention is to provide a device by which thecenter of rotation of the work-piece may be positioned tangentially orin other than tangential relation with respect to a shaped punch,whereby a circular work-piece may be formed with either an essentiallysmooth edge or a contoured edge such as possessed, for

example, by a circular saw of the disc type.

A still further object is to provide a device which may be availed of tohold work-pieces securely, yet so that they may be readily attached andreleased, without in any way imparing or marring the surfaces of thework-pieces or necessitating the formation of center punch holes or theuse of screw fastening means, although the device may be employed inconnection with center holes and carries screw fastening means which maybe utilized, if desired.

A still further object is to provide a device which is unitary incharacter and which possesses features enabling it to be employed as anattachment, being available tion with existing machines withoutstructural changes thereof.

Yet another object is to provide a device which may be attached to themachine with which it is to be associated in such a manner that theworkas such for use in connec- I 2 pieces held thereby will be in thedesired relation with performing instrumentality.

A still further object is to provide a device having a novel design andarrangement of parts, whereby to attain simplicity in construction and,when the device is employed as an accessory, to facilitate itsattachment to and its detachment from the machine with which it isassociated.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 is a fragmentary perspective view of a punch press showingassociated therewith, as an attachment, a device embodying the featuresof the invention;

Figure 2 is an enlarged vertical sectional view taken along line 22 ofFigure 1;

Figure 3 is a fragmentary view taken along the same section line showingthe center pin of the holder extended to an operative position;

Figure 4 is an enlarged elevational View, partially in section, of themounting post end of the device as it appears along line 4-4 of Figure1;

Figure 5 is a vertical section taken along line 5-5 of Figure 4;

Figure 6 is a detail section taken along line 66 of Figure 4; and

Figure 7 is a similar section taken along line !1 of the same figure.

The device, indicated generally at It in Figure 1, is illustrated by wayof example in connection with a punch press which is sufiicientlyillustrated for the purpose in view by a showing of the head H in whichthe ram (not shown) operates and the bed I?! which carries a removablepunch holder l3 in accordance with the teaching of Figures 13, 14 or 15of patent 2,364,011, assigned to our interests.

The punch holder [3, as illustrated herein, has a forwardly-extendingarm 14 which carries a work-performing tool l5 (punch) at its outer endwith which the press ram cooperates and which in turn cooperates with asuitable die (not shown) carried by the punch holder under theworkperforming tool. A T-slot 13a is formed in the holder 13 to enablevarious attachments to be removably and adjustably secured to the pressbed, the said slot extending lengthwise of the holder and being open atits forward end.

It is contemplated that the device may, if desired, be employed as anattachment for a machine tool of the type generally described; and whenso employed the T-slot l3a may be availed of for attaching it to thepress. For this purpose, the head it of the device is carried by ansupported accurately respect to the workarm ll, the inner end of whichis carried by a post l8. The latter, as best shown in Figures 4, 5, 6and '7, includes a central bolt l9 which, at its lower end, extends intothe T-slot l3a and carries in the wide base portion thereof, anelongated bar 20 which, when loose, may move lengthwise of the T-slot.The bolt i9 extends upwardly through a cone-shaped element 2! whichseats upon the holder !3 and which in turn provides a seat for a sleeve22, the latter having a conical recess at its lower end which in taperconforms to that of the seat portion of the element 2 At its upper end,the sleeve 22 is cut away at one side of the opening which accommodatesthe bolt is to provide a shoulder 23 on which the inner end of the armll is supported, the latter being held on the said shoulder by acap-piece 24 which on opposite sides has depending flanges 25 and 26.

The former engages the outer side of the arm ll while the latter has abeveled inner wall which engages a correspondingly inclined flattenedarea at the top of the sleeve 22. A nut 2'! on the threaded upper end ofthe bolt it may be turned in one direction to loosen the parts of thepost assembly and thereby enable it to be adjusted along the T-slot sothat the device as an entirety may be adjusted with respect to the pressbed and so that the arm ll may be adjusted lengthwise on the shoulder23, the device being secured in the desired position of adjustment andthe arm I! being clamped thereto by tightening the nut 21. To facilitateadjustment of the device and arm in the manner described, the postassembly may, as illustrated, include a wrench 21a. So that it may bereadily available, the latter may be removably secured to the postassembly by a nut 28, the nut 2? having a round neck portion 29 so thatthe wrench may be moved either to the position shown or to a position inwhich it is located between the top of the nut 21 and the under side ofthe nut 28. In the latter position, the wrench is inoperative and mayrest upon the corner shoulders of the nut 21.

It will be apparent that upon tightening of the nut 21, the bar 29 byengaging the under sides of the overhanging walls of the T-slot willresult in all of the parts of the post assembly being urged downwardlytoward the press bed. Thereby the cone-shaped element 21 will be forcedtightly against the upper surface of the punch holder !3 while thecooperating inclined surfaces on the element 2 sleeve 22 and cap-piece2% will cause all of the parts of the post assembly and the arm H to bewedged together and rigidly secured to the punch holder and to oneanother.

In order to insure against any relative movement between the postassembly l8 and the punch holder 13, the cone-shaped element 2! carriesdownwardly tapering pins 39 which enter the neck of the T-slot lie atopposite sides of the bolt l9, the degree of taper of the pins beingexaggerated for purposes of clarity. The pins 36 are engageable with theside walls of the neck portion of the T-slot liia as the parts of thepost assembly are tightened in the manner described. By their engagementwith the walls of the T-slot the pins 36 are operative, therefore, tolock the post assembly to the punch holder it, or press bed, against anyangular or lateral movements which would be transmitted to the head it.

The head N of the device includes a slide 3i which is adjustable alongthe arm I1 and which carries a set-screw 32 for locking the slide in anydesired position of adjustment along the arm.

At one side of the arm ll, the slide 3| is formed with a threaded borefor accommodating a threaded sleeve 33. The latter is flanged at itsupper end to provide a wheel 34 and surrounds a cylinder 35, the upperend of which carries a split ring 36 which engages the hub portion ofsleeve 35 at the juncture of the latter and the wheel as. Hence, thewheel 34 may be grasped and manually turned in one direction to lowerthe sleeve 35 and the head [6 carried thereby and may be turned in theopposite direction to elevate the sleeve and head.

At its lower end, the cylinder 35 carries a disclike member 31 which,although illustrated as circular in shape, need not necessarily be so.

On its under side, the member 3? is formed with a marginal channel 38for accommodating an O-ring 39 or other suitable sealing element, one ofthe side walls of the channel 38 preferably being undercut, asillustrated, to restrict the entrance to the channel so that the sealingelement may be forced into the channel and will thereafter remain there.It will be noted that the depth of the channel 38 is slightly less thanthe diameter of the O-ring. Consequently the O-ring projects from thechannel 38 only far enough to insure firm sealing engagement between itand the work-piece 40. Preferably the marginal edge of the member 31,that is the rim portion located exteriorly of the O-ring 39, terminatesshort of the plane of that portion of the under face of the member 3'1which is located within the confines of the ring 39, whereby to assureatmospheric pressure forcing the O-ring 39 against the side wall of thechannel 38 to provide a tight seal.

The member 3! is secured to the lower end of the cylinder 35 by athreaded plug 4| which screws into a threaded recess in the under sideof the member 31 and against the flanged lower end of the cylinder,there being a suitable packing 42 between the flange on the cylinder andthe marginal portion of the member 31 which surrounds the openingthrough which the cylinder extends. Preferably the parts are so designedthat when the threaded plug 4! is screwed into place its under side willbe co-planar with the under side of the member 31. The area of the underside of the member 3'! which is delimited by the O-ring communicateswith the interior of the cylinder 35 through a passage 13.

The cylinder 35 accommodates a plunger 54 which is reciprocable thereinbut which is normally held at the upper limit of its range of movementby a spring 45. The latter surrounds the shank 46 of the plunger, beingunder slight compression between the upper end of the cylinder 35 andthe under side of a head 41. The plunger is formed with an annularchannel G9 which accommodates a combined valve and sealing element 50,the latter being in the form of a ring of rubber or other sealingmaterial and, owing to its engagement with the wall of the cylinder 35,offering some resistance to movement with the plunger 44. The width ofthe channel 49 is such that some axial movement of the element 50 in onedirection in the channel 49 is permitted when the plunger M is depressedand some axial movement in the opposite direction in the channel ispermitted when the plunger is released and moves in the direction of itsnormal position. Such movements of the ring 58 aer utilized to controlthe port of a slot 5|, the said port communicating with the channel 49at the upper side thereof, being closed by the ring 50 when the latteris located at the lower side of the channel 49, as shown in Figure 2,and being open when the ring is located at the upper side of the channel49. It will be apparent from the foregoing that the plunger 44 may bemoved downwardly against the action of the spring 45, during whichoperation any air in the cylinder below the plunger will be permitted toescape past the ring 50 and through slot there being suitable clearancebetween the plunger and the walls of the cylinder 35 at the oppositesides of the ring 50 to permit the passage of air in the amountsinvolved.

Upon release of the head 41 of the plunger, the spring 45 willautomatically act against the head and tend to restore the plunger toits normal position. Such movement of the plunger 44 is accompanied byseating of the sealing ring and valve, whereby as the plunger movesupwardly air will be drawn from the under side of the member 37 into thecylinder 35. If at such time, therefore, the member 37 is pressedagainst a workpiece so that the O-ring 39 seals off an area thereof,then a vacuum will be created under the said member so that atmosphericpressure will force the work-piece tightly against the member. In thisconnection it will be noted that the volumetric capacity of the vacuumchamber provided at the under side of the member 3! is very small withrespect to that of the cylinder occupied by the plunger 44, the saidvacuum chamber being of the order of .005 of an inch high. By this meansthe mechanical advantage of the spring 45 is greatly multiplied, sinceit can operate a comparatively small plunger 44 to rapidly exhaust theminute volume of air under the member 3! to produce a high degree ofvacuum from a very small force from the spring 45. Fatigue of theoperator in high production work is thereby avoided. As a consequence ofthe high vacuum produced in the chamber at the under side of the member31, firm engagement of the workpiece with the said member is insured. Inthis connection it will also be noted that in Figure 2 device isillustrated resting upon a work-piece which in turn is resting upon thepunch holder, or press bed l3, and that the plunger 44 is shown at theupper limit of its range of movement. It will be understood when theplunger is forced downwardly and released in the manner described(assuming the head of the device is pressed against a work-piece) itwill not return to the upper limit of its range of movement. It willmove upwardly only until the atmospheric pressure acting against theplunger 44 balances the force exerted by the spring 45. As the upwardmovement of the plunger 44 creates the vacuum behind the work-piece andas such movement is efiected by the spring 45, the latter may be made ofthe desired strength and compressed to any desired degree between thetop of the cylinder 35 and the head 41 to produce the desired degree ofvacuum. The plunger may be operated a number of times if the desireddegree of vacuum is not produced the first time. To relieve the vacuumunder the head it, it is only necessary to force the plunger 44downwardly. By doing this, the work-piece may be readily released bysliding it out from underneath the member 31. In high productionoperations, a sudden blow on one side of the work-piece, to cause theentry of air, will generally effect its release.

The O-ring 39 seals the vacuum chamber behind the work-piece and alsoprovides a fricthe head of the iii) tional surface which, in response tothe pressure of the work-piece against it, will prevent any relativemovement between the work-piece and member 31.

The cylinder 35 is journalled in the sleeve 33 for free rotary movement.When the work-piece, therefore, has been secured to the head IS in themanner described, it may be turned freely with respect to the axis aboutwhich the head turns. If, therefore, the work-piece is located in thedesired relation with respect to the punch IS, the work-piece may beturned so that, assuming a. nibbling operation is contemplated, thework-piece will be formed with a circular edge, or perforations may beformed along a circular path.

It will be understood that in adjusting the head IS in the desiredrelation with respect to the work-performing tool, the post assembly 43may be adjusted lengthwise of the T-slot Ita the arm ll may be adjustedlongitudinally with respect to the post assembly, and the head !6 may beadjusted lengthwise of the arm. The post assembly 18 also provides forangular adjustment of the head 16 about the axis of the bolt 19 of thepost assembly. It will also be obvious that arm Il may be replaced by alonger or shorter arm for certain operations.

As shown in Figure 1, a line 60 is scribed on the machine table l2. Whena shaped punch is used such as illustrated in the drawings ofapplication Serial No. 69,954, assigned to our interests, the centerscrew 55 and its point 56 are extended and the device is adjustedradially with the point 56 following the scribed line 60. This assuresthat a fore and aft keyed straight sided punch will always out a tangentto the center of rotation of the head, thereby providing a finished edgework-piece. offsetting the center will provide a contoured edge such ascharacterizes a circular saw disc.

To facilitate positioning of the work-piece so that the center thereofwill be located in alignment with the axis about which the member 3?turns, the work-piece may be initially scribed or otherwise marked withan outline conforming to the marginal edge of the member 3'! in such amanner that such marking will be visible and serve as a guide toindicate when the head and work-piece are properly located with respectto one another.

The member 31 may be elevated and lowered, at will, with respect to theplane of the top surface of the press bed by turning the sleeve 33.

' Thereby th initial engagement of the member 31 with the work-piece isinsured while at the same time provision is made for supporting thelatter at any desired elevation with respect to the work-performingtool. Preferably the sleeve 33 is elevated slightly with respect to themember 31 so that the axial play which is thereby provided between itand the member 35 permits pressing member 37 against the work-piece andraising it to force the work-piece off in the previously describedproduction manner. In other words the work-piece during the operation ofthe tool may lightly contact the press bed or it may be supported whollyabove the press bed. When desired, the sleeve 33 may be secured in itsadjusted position by a set screw 33a. If, as in some cases, the die withwhich the work-performing tool cooperates projects a short distanceabove the press bed, a shim may be located below the work-piece duringthe operation in which the work-piece is positioned under the head l6and 7 the plunger 44 operated to produce the desired vacuum, the shimbeing operative to support the work-piece in the plane of the top of thedie during this operation.

The vacuum arrangement for supporting workpieces has the advantage thatthe drilling of center holes and the like therein is avoided. it isavailable in any instance in which the upper surface of the work-pieceis not porous, oily or pitted in such a manner as to prevent thecreation of the desired vacuum under the member 3?, or to release suchvacuum by leakage when once produced.

The device, however, is so designed that it may be availed of, ifdesired, to hold work-pieces by center pin and screw methods.

To this end the plug 41 of the member 31 carries a combination centerand pickup screw 53. The shank portion of the latter occupies a threadedbore 54 in the plug ll and has a head 55 which occupies the enlargedentrance of the bore, the head 55 being formed, or provided, with apoint 56 which may be extended, by unscrewing the screw 53, to aposition beyond the plane of the lower surface of the O-ring 39, as bestshown in Figure 3. As so extended, the point 55 may be caused to enter acenter punch mark in the work-piece. This may be accomplished first byextending the point 56 in the manner described and then turning thesleeve 33 to cause the point 56 to enter the center punch mark, it beingapparent that this will occur before engagement of the work-piece by theO- ring 39. Thereafter the work-piece may be turned about the point 56without interference from the O-ring 39 or any other part of the head16,

In such instances in which the work-piece extends substantially beyondthe top of the press bed when in the desired relation with respect tothe work-performing tool and when it, therefore, may be desirable toattach the work-piece to the head by screw means, the work-piece may bedrilled or otherwise formed with a hole of a diameter slightly largerthan that of the shank of the pickup screw 53. Th latter may then beremoved and the shank thereof inserted through the hole in thework-piece after the work-piece is properly located against the head.The pickup screw may then be screwed in place and tightened so that itshead engages the workpiece.

It will be apparent that the device described has the advantage thatwork-pieces may be supported by it in various ways, in each of which theworkpiece will be firmly attached to the head and in each of which thehead will be supported in such a manner that while it may be turnedfreely, any appreciable deflection of the head with respect to thework-performing tool will be prevented.

The embodiment of the invention which is illustrated is intended by wayof example only as various of the advantages noted may be attained inconnection with various modifications coming within the purview of theinvention.

W e claim as our invention:

1. A device of the character described com prising a head which isrecessed on one side to provide a closed channel therein, an elasticgasket positioned in said channel, the depth of said channel being lessthan the thickness of said gasket, whereby said gasket projects beyondsaid one side of said head so as to be engageable with a workpiece andseal off a predetermined area thereof, the portion of said one side ofsaid head within said gasket being plane, and the portion of said oneside of said head exterior or" said gasket being disposed back of saidplane portion so that atmospheric pressure may act against the exposedoutside of said gasket when said gasket is engaged with a workpiece, toseat said gasket against the inside wall of said channel, a cylinder, aduct connecting said cylinder with said one side of said head within thearea enclosed by said gasket, a plunger reciprocable in said cylinderand manually movable therein in one direction, resilient means forautomatically moving said plunger in the opposite direction whenreleased to suck air from the space which is enclosed by said gasket,and a valve movably mounted in said plunger and movable to open positionto permit escape of air from said cyiinder ahead of said plunger whensaid plunger is moved in said one direction, said valve being closed onmovement of said plunger in said opposite direction, the area enclosedby said gasket being much greater than the area of said plunger.

2. A device of the character described comprising a head which isrecessed on one side to provide a closed channel therein, an elastic O-ring positioned in said channel, the depth of said channel being lessthan the thickness of said O-ring, whereby said O-ring projects beyondone side of said head so as to be engageable with a workpiece and sealoff a predetermined area thereof, the portion or said one side of saidhead within said O-ring being plane, and the portion of said one side ofsaid head exterior of said O- ring being disposed hack of said planeportion so that atmospheric pressure may act against the exposed outsideof said O-ring when said O-ring is engaged with a workpiece, to seatsaid O-ring against the inside wall of said channel, a cylinder, a ductconnecting said cylinder with said one side of said head within the areaenclosed by said G-ring, a plunger reciprocable in said cylinder andmanually movable therein in one direction, resilient means forautomaticaily moving said plunger in the opposite direction whenreleased to suck air from the space which is enclosed by said O-ring,said plunger having a peripheral recess, a sealing ring mounted in saidrecess, the thickness of said ring having less than the axial length ofsaid recess, and said plunger having a passage therein connected withthe upper end of said recess through which air may escape when saidplunger is moved in said one direction.

3. A device of the character described comprising a head which isrecessed on one face thereof to provide a closed channel spaced from theperiphery of said head but extending around the head adjacent itsperiphery, an elastic O- ring positioned in said channel, the depth ofsaid channel being slightly less than the thickness of said O-ringwhereby said O-ring projects slightly beyond said one side face of saidhead so as to be engageable with a workpiece and seal off apredetermined area thereof to provide a chamber, the portion of said oneface of said head, which is exterior of said O-ring, being disposed backof the remaining portion of said head which lies within the perimeter ofsaid O-ring, so that atmospheric pressure may act against the exposedoutside portion of the O-ring to seat said O-ring against the insidewall of said recess, when said O-ring is engaged with a workpiece, acylinder, a duct connecting said cylinder with said one face of saidhead within the area enclosed by the perimeter of said O-ring, a plungerreciprocable in said cylinder, said plunger being manually movable in ondirection in said cylinder, resilient means for automatically movingsaid plunger in the opposite direction when the plunger is released tosuck air from the area enclosed by said O-ring, said chamber having avolumetric capacity which is small with relation to that of saidcylinder and an area which is large with relation to that of saidplunger.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Number 15 204,484

Name Date Cuthbert Feb. 12, 1889 Robinson Mar. 19, 1901 Church Oct. 15,1912 Young Feb. 8, 1916 Becker Sept. 26, 1922 Parker July 19, 1938Legassey June 30, 1942 Forsman Nov. 15, 1949 Ward Sept. 26, 1950 Lewiset a1 Jan. 20, 1951 FOREIGN PATENTS Country Date Canada Oct. 5, 1920

